Receiving perforator



1927. M H. ANGEL 4 RECEIVING PERFORATOR Filed July 21. 1925 3 V q) gwuemkw Haw! Angel 7 mm L +1 m aw Sq E w QR m G I M4 H Patented May 24, 1927.

rim-TED STATES PATENT o-FFrcE.

HERBERT. ANGEL, or BROOKLYN, NEW YORK, essrenonro'rrrn WEs'r Rn Union TELEGRAPH COMPANY, OF NEW YORK, N. 1., A oonPoRA'rmN OF N W YORK;

RECEIVING PEREOEATOR.

A lication filed J'u1y21. 1925. Seria1 No.'45;O0 2.

This invention relates to automatic telegraph receiving apparatus and particularly to the type of receivers used in ocean cable operution which record the messages or signals in the form of perforations in a tape. The object of this invention is to increase the etiiciency and reliability of'apparatus of this type and to enable the apparatus to operate at greater speed with accuracy.

Receiving perforators at present developed are not reliable and will not record the code signals accurately when connected tothe receiving circuit of an ocean cable. This is due mainly to the fact that the signals are received the end of an ocean cablein the form of block signals wherein the successive unit impulses of like sign are merged into a single prolonged impulse hava length or 1 eriod equal to the number of like unit impulses in the gnal character. Owing to the necessary operation of the perforator mechanisn, which stops the tape for an instant each time the punch is opa'utec, itis evident that'the driving motor must normally tend to rotate at a greater s eed than that of the transmi er in. order to compensate the time cons .ed in the punching operations and. must be corrected so that the resultantsieed .of the tape shall be in synchronism with the transmitterand the receired signals. Heretoi'ore there has been uo-ineans of applying a correction to maintain the'pe'rforatorin accurate synchronisin with the transmitted signals except at each received signal and as the block signals extend over a period of several unit impulses the perforator would a-:.ha1ice beyond synchronous speed during the transmission of a single blocksignal. It has therefore been impossible heretofore to use receiving perforators on ocean cables which were operated according to the usual practice.

The purpose of my invent-ion is to provide means for maintaining the pe-rforator in exactsynchronism with the transmitter and the received signals. 'To this end I provide means for breaking up the block signals into separate impulses corresponding to the component unitimpulses transmitted and cause each of these unit impulses to govern or control the perrorator. In this manner it is impossible for the speed. of the 'perforator to depart from synchronism with the transmitter or received signals and the resulting perforated tape is an exact replication.

In the following descriptionof my invention, I shall refer to the accompanying drawings, in whichFigure l is a diagrammatic illustration of one organization of apparatus and circuits embodying m'yinven of the original tape at the transmitter station; Figure 2 is a detailed View of the camactuated circult controller for the impulse interpolat ng relays; Figure 3 ls a detail I have shown a perforating device P of a. well known construction. The tape 6, which has been previouslyprovided with a ce'ntral'row of" feed holes, moved over the punch block't'by the tapefeed wheel 8 carriedbycthe shaft 9 which is driven by the motor: l0,through the gears ll and .12, the worm gear 13 and worm wheel 14.

through the tape for the dot and dash impulses respectively, of thecode characters, are actuatedby the hammer 2O carried'by the punching shaft 21, having a head 23 moving in the cam-slot 2st inthe drive shaft .25. whereby the hammer is reciprocated toward and from the punches. The hammer is shifted laterally over one or the other punch, depending upon whet-her thesignal impulse represents adot or a dash in the code character. The drive shaft connected to the motor shaft 26 through a friction clutch, represented by a disk Q'Tfast on the shaft 25 and'friction shoes 28, secured to shaft 26 and held against the disk by a springSO. The worm wheel it is permitted to slip on the shaft- 9 being frictiona'lly held against a collar 15 by the spring 16 held'by' a nut'l'l'. H

The driving motor 10 "is maintained in ex act synchronism with the signal impulses in the manner hereinafter described. :Vfhen no signal impulse is received, the shaftQB' is driven through-the friction clutch 2?. As

the shaft rotates the cam-slot causes the rod 36 to descend forcing the wedge *3T-into the teeth o f'thewheel 38 and stopping the I a Thepunches 18 and 19, which punch the holes magnet moves the rod 41 and shifts the hammer 20 over the punch 18 or 19, depending upon whether the signal corresponds to a dot or a dash impulse. Immediately thereafter, the arm 21 is moved downwardly by the cam-slot 24 thereby causing the hammer to drive the selected punch through the tape 6. The further rotation of the shaft 25, causes the cam-slotQt to move rod 43 downwardly thereby forcing the wedge 45 into the adjacent slot in the correcting wheel 46, just as the wedge 37 is withdrawn from the stop wheel 38, permitting the tape feed ing shaft 9 to rotate. The slots in the correcting wheel 46 are so inclined that the entrance of the wedge 45 causes the wheel and the shaft to slip forward an amount equal to that which was lost while it was held by the stop wedge 37 during the operation of the punch.

The signals coming in over the ocean cable are received in the usual manner upon a drum relay 50, which actuates the local (lot relay 52 or the dash relay 53 as the needle 51 is moved over to one side or the other of the drum in accordance with the polarity of the signals. The signals are received as block. signals as indicated in Figure 4.

Thus the letter I has a length equal to two unit impulses, the letter S being equal to three unit impulses and the letter H having a period of four unit impulses. It is evident that the recording apparatus must be maintained in exact synchronism with the incoming signals at all times in order to faithfully reproduce the signals. When a tape perforator is employed as the recorder, its speed must be governed with the greatest exactness as the slightest departure from synchronism causes a mutilation of the signal. While receiving perforators have been successfully used on land lines in which each unit impulse of a code character is transmitted and received. it has heretofore been impossible to use a perforator as a recorder on ocean cables because of the fact above stated that the signals are received in block form which does not permit a sufficient number of corrections to maintain the perforator in synchronism with the signal impulses. It has been found necessary to arrange the parts so that the speed of the perforator shaft shall be slightly faster than the speed of the distant transmitter. The shaft 25 of the perforator makes one rotation for each unit signal impulse and when this is corrected at every revolution, absolute synchronism and phase relation is maintained. If, on the other hand, correction can only be made once in several revolutions, the shaft will have an opportunity to gain speed to an extent sufficient to throw the perforator out of synchronism thereby rendering it anunreliable instrument.

To overcome the difiiculties and defects above pointed out, I have devised an organization for causing each impulse received over the cable to control and maintain the speed of a synchronous governor for the driving motor, thereby correcting any tendency of the motor to depart from synchronism; and for separating the block signals into their component unit impulses and causing the perforator to stop and punch the tape for every unit impulse. By this means the speed of the perforator is controlled during each unitary component of each block signal and hence any departure from absolute synchronism with the received signals is absolutely prevented. I have thus made possible the use of a receiv ing perforator on ocean cables. The tapes which have been perforated at the receiving end of a cable may be used in a tape transmitter to repeat messages into another cable or line, so that messages may be repeated from one cable to another automatically and without manual control. This not only eliminates errors due to mistakes of an op erator but greatly increases the capacity for handling traflic over the cables.

Referring to the accompanying diagram, if a block signal is received which causes the needle of the cable relay, to move onto the left hand conducting portion of the drum, a circuit is closed from the local battery 56 through the coils of the dot relay 02, causing its tongue or arn'iature to move over against its making contact M. A circuit is thereby closed from minus battery through the tongue of relay conductor 57, and fork control relay 58 to ground. As the tongue of relay 58 moves over against its marking contact M, a current flows from plus battery charging condenser 60 and en ergizing magnet 61, which exerts a quick pull on the tines of the tuning fork or vibratory reed 63. This tuning fork or reed has been previously set into vibration and the weights have been adjusted along the tines of the fork until they vibrate in synchronism with the distant transmitter or unit si nal impulses received over the czble. tile for]: has been set into vibration it will continue to vibrate at fixed rate for a considerable period. lVhen the marking impulses received over the cable energize the fork magnet (31, the fork is not only given an impulse to maintain its vibrations but the impulse either assists or retards the natural vibration to thereby correct any departure in phase from exact synchronism if any cxists. The synchronous vibration of the fork is thus established and corrected directly by the signal impulses. Upon the deenergization of the relay its tongue moves back to its spacing contact S and the con denser is discharged through resistance 6?.

The motor 10 which drives the shaft of the perforator P, is operated froma direct current source and is of the constant speed type. The rheostat in circuit with the armature is adjusted until the speed is substantially synchronous with the speed of the signal transn'iission, which can be determined by the flashes of the lamp 70. The motor is provided with a winding and slip rings by which an alternating current may be taken off and connected to the secondary winding of a transformer 71. The primary Winding is connect-ed to contacts 72 and 73, which are alternately engaged by the con tacts carried by one of the fork tines. The middle or neural point of the primary winding is connected to minus battery. As the fork alternately engages the contacts 72 and 73, a current flows from plus battery through fork 63, through conductor 74: or 75, and through one half or the other half of the transformer primary to minus battery. Thus the vibrations of the fork alternately send current through the two halves of the transformer primary and this in tur produces an alternating current inthe secondar' winding which is connected through the slip rings with the alternating current winding on the armature of motor 10. hen the direct current side of the motor armature is adjusted to a speed approximately synchronous with the frequency of the alternating current induced by the impulses from the fork circuit, the latter induced currents will pull the motor, into exact synchronism with the vibrations of the fork and thereafter operate it as a synchronous motor, the latter operating substantially as a rotary converter. The speed ofthe motor is thus under the direct control of the signal impulses received over the cable. Tt'is obvious that an impulse motor controlled by a vibrating fork may be used as a driving means, but the motor and method of control just described has the advantage of being self-starting.

I have previously explained the necessity for separating the block signals into their component unit impulses before introducing them into the magnet whi h controls the stopping of the perforator shaft. 13 or this purpose I connect the conductor (which carries the block signals from the dot and dash relays 52 and to the coils of the polar interpolating rela 's 76 and 7S andthrough conductor 59 to a pair of circuit breaking contacts 79 controlled by acam on the motor shaft. As the cam makes one revolution during a unit signal period, the circuit through the interpolating relays 76 and 78 will .be broken after each unit impulse and consequently the tongues of these relays will move between their S and M con tacts during the transmission of each block as many times as there are unit impulse periods in the block signal. Thus if the block signal for the letter H is transmitted over. the conductor 57, the circuit throu h the interpolating relays76 and 78 and the conductor 59, Will be broken four times at the contacts 79 by the, cam 80, since the latter Will make four revolutions during that period. Hence the prolonged impulse for the letter H shown in Figure l, is broken up into four short impulses shown in Figure 5. In order to separate these four unit impulses from each other, the cam 80 is so constructed (seeFig. 2) that the circuit 18 broken at the contacts 7 9 for a certain pro-' 78, and conductor to minus battery.

Thereupon the armature of magnet 40 moves to its left hand stop'L and causing the link 41 to shift the hammer 20 into alinemeut with the dot punch 18. lVlien a signal is received corresponding to a dash code character, the polar relay 78 will be actuated and the current from plus battery will flow over conductor 84 and through the coils of magnet 40 in the opposite direction, thereby causmg its armature to swing over agalnst 1ts R stop and the hammer 20 will then be shifted into alinement with the dash punch19.

Simultaneously with the action of the punch magnet 40, the release indent relay 87 was operated which is in ashunt circuit with conductor 82 and therefore in series with punch magnet e0. The tongue of relay 87 normally rests against its left hand contact L. thus closing a circuit from minus battery through conductor 89 and the coils of detentmagnet 90, which holds its armature against its. right hand stop R and causes the free end of the arm 31 to engage the detent 32 and stop the rotation of'the perforator shaft 25. lVhena signal impulse is received which actuates either of the relays 76 or 78, a circuit is closed through relay 87, causing its tongue to move over to its right hand contact B. This sends a current from plusbattery through magnet 90 which moves the arm 31 to release the detent and permit the rotation of the perforator shaft. It will be observed that the relay 87 and detent magnet 90 are actuated with every actuation of either ofthe interpolating relays 7 6 and 78 and hence the arm 31 will engage the detent 32 after every unit si nal imnulse..com rised 1n the block.

signal. Accordingly the detent 32 will be engaged by the arm 31 to stop the rotation of the perforator shaft three times during the reception of the code letter S, four times during the reception of the code letter H and live times during the reception of the figure as will be apparent from Figure 5.

I have illustrated and described one arrangement oi apparatus for carrying out my method of operating a recording tape pertorator at the receiving end of an ocean cable but it will be evident to telegraph eng neers and those familiar with the construction and operation of telegraph systems that other apparatus may be used in association with the cable relay for separating the block signals into their component unit impulses such as the regenerative rotary repeaters disclosed in the patent to Foll No. 1,535,073 and in the application of Peterman, Serial Number 557,048, filed April 28, 1922. I intend, therefore to cover in my claims such other arrangements as may be considered within the scope ot my invention.

I claim:

1. The method of recording"telegraph rode characters, received as block signals at the receiving end of an ocean cable upon a motor driven tape per-i erator, which comprises separating the block signals into their several component unit impulses, transmitting said unit impulses in sequence to the tape pcrtorator and causing the received signals to control the speed ot the driving motor to thereby maintain the pertorator in synchronism with the signals.

2. [an organization for recording telegraph code characters received from a cable in the form of block signals, comprising a cable relay for receiving the signals in block term, means for separating said block signals into their component unit impulses, a tape perforating mechanism provided with automatically operating punching devices and punch selecting means, means for driving said mechanism at a substantially uniform speed, and means actuated by said unit impulses 'l'or momentarily arresting said mechanism after each impulse, and simultaneously operating said selecting means.

3. In an organization as set forth in claim 2, means controlled by the received signals for maintaining said driving means in synchronism with the speed of transmission of said signals. 7

l. Apparatus for receiving and recording telegraph signals from an ocean cable, comprising a cable relay actuated by the block signals received from the cable, a tape peri'orator provided with punch selecting means and with a stop device, a continuously operating motor for driving said perforator,'

means for separating said block signals into their component unit impulses, and means for causing said unit impulses to actuate said selecting means and said stop device.

Apparatus for receiving and recording telegraph signals from an ocean cable, comprising a cable relay actuated by the block signals received from the cable, a tape periorator provided with punch selecting means and with a stop device, a continuously operating motor for driving said pertorator, means for controlling the speed of said motor by said 1' ceived signals, means for separating said block signals into their component unit impulses, and means for causing said unit impulses to actuate said selecting means and said step device.

(3. In an apparatus as set forth in claim t, a member having a natural period of motion, and electromagnetic means associated therewith and controlled by the received signal impulses for controlling the speed of said motor.

Apparatus for receiving and recording telegraph signals from an ocean cable, com prising a cable relay actuated by the block signals received from the cable, a tape pertorator provided with punch selecting means, a continuously operating motor for driving said pert'orator, means for controlling the speed of said motor by said received signals, means for separating said block signals into their component unit impulses, and means for causing said unit impulses to actuate said selecting means.

In testimony whereof I atlix my signature.

HERBERT ANGEL. 

